Stay-cutting attachment for sewing-machines.



B. v. KEH SHNER. STAY CUTTING ATTACHMENT FOR SEWING MACHINES.

APPLICATION HLED JULY 18, I910.

1,169fl88. Patented Jan. 18, 1916.

l yl 5 4 D 1 a v t E Q Ti 0' 532% P f B. V. KERSHNER.

STAY CUTTING ATTACHMENT FOR SEWING MACHINES.

APPLICATION FILED JULY I8. 1910.

1,1fi9fl88, Patented Jan. 18, 1916.

2 SHEETS-SHEET 2- an s ra rns rarnn'r ora ion.

BENJAMIN V. KERSHNER, OF CHICAGO, ILLINOIS, ASSIGNOR T0 UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

incense.

Specification of Letters Patent.

Patented Jan 1%, 19116.

- Application filed July 18, 1910. Serial It 0. 572,449.

To all whom it may concern:

Be it known that I, BENJAMIN V. KERsH- NER, a citizen of the United States, residing at Chicago, in thevcounty of Cook, State of Illinois, have invented certain new and useful Improvements in Stay-Cutting Attachments for Sewing-Machines, of which the, following is a description, reference being An object of the invention is to improve the details of the attachment whereby the cutting action is rendered much more effi cient, and whereby the tape is properly guided through the cutting attachment, and

directed to the stitch-forming mechanism.-

The invention consists in the parts, im-

provements and arrangements hereinafter shown, described and set forth in the appended claims.

In the drawings which show by way of illustration one embodiment of the invention, Figure 1 is a plan View of a work sup:

port, with my attachment applied thereto;

Fig. 2 is a front viewof the same. Fig. 3 is a plan view from therear of the attachment underneath the bed plate of the machine. Fig. 4 is a sectional view through the bed plate and the attachment. Fig. 5 is a plan view of the attachment with the stationary shearing blade removed. Fig. 6 is a detail showing the two cutters and the guiding finger for keeping the same in proper position. Fig. 7 is a'section' through the two cutters.

The bed plate 1 to which my attachment is applied, may be of any desired type, and

is provided with a throat plate 2 having feed slots in which the feed dog 3 operates. As herein shown, I have provided a throat plate with two needle slots 4:, 4. At the front side of the work support are two spaced raised. portions 5, 5, which are cut away to form ledges 6, 6, on which rests the stationary shearing blade 7. Between the ledges 6, 6, the bed plate is further'cut away to form a guiding recess through which the the side of the bed plate and the stay strip is guided underneath said loop. Located underneath the shearing blade and in the guiding recess for the tape are two edge guides 9 and 10, each of which is slotted and secured to the bed plate by a suitable screw The edge guides 9 and 10 are-spaced so as to engage the edges of the stay strip and will direct the same properly to the feed of the machine, and the stitch forming mechanism. When a wider strip is used, the screws 11 may be released and the edge guides adjusted to accommodate the same. The movable cutter 12 is held in sliding engagement with the apron 13 depending from the bed plate, by a guiding plate '14. "A spring 15 secured to the guiding plate 14, is bent laterally at its upper end, and projecting through a notch in the upper edge of the guiding plate 14;, rests against the movable- 'knife and holds the same in close shearing contact'with the stationary shearing blade. The knife 12 is beveledto form a cutting edge 16 at its upper end, and at one side of the cuttingedge is a projecting. finger 17 which remains in constant contact withthe edge of the stationary shearing plate vor blade. This guiding finger 17 is pressed by the spring 15 into close contact with the shearing blade, and serves as a means to guide the knife when it is below the shear ing blade. The stationary shearing blade 7 is slotted at 18 and the screws 19 adjustably hold said stationary blade in its seat in the work support. This stationary blade may be quickly removed/and ground so as to providea very sharp cutting edge whlilclhev coiiperates with the movable blade. blade may also be readily adjusted to take up the wear and the cutting away by grinding.

The cutter is raised so as to shear the stay strip by a rock shaft 20, which is mounted in suitable bearings 21, 22, carried by the bed plate. A lever 23 is connected to the rock shaft and is provided with suitable openings 24 to which a treadle may be attached. Aspring 25 encirclesthe rock shaft and is connected at one end to the lever 23,

i and at its other to a stud 26 secured to the bar 22. This spring is so wound as to normally hold the lever 23 raised.

Astop screw 27 limits the upward movem'entof the lever 23 by contact with the i apron 13 oftne bed plate. A lug 28 is carried by a plate 29 "that is secured tothe rock \lowered or retracted y a Spring which shaft'in any desired 'Way, so that as the rock shaft'is" oscillated the lug 28' moves therewith. This lug 28 is located in a recess 30 formed in the lower end of the movable cutting blade 12. The movable cutting blade is is carried by a screw stud 32 and rests against. the pin 33 formed in thelower end of the; cutting rblade. A lug 34 carried by the movable blade 12 engages the bottom of the recess formed in the guiding plate 14, and limits the downward movement of the movable knife.

r The adjustable screw 27 is preferably so set that the lever .23 continues its upward movement after the blade has reached the extreme of its downward movement, and

the'lug 28 will be moved away from the lower end of the knife. The rock shaft carries an arm, 35' on which is pivoted a feed finger 36. A spring37 is wound around the pivotscrew of the feed finger and normally holds said feed finger in engagement with the under face of the stay strip. When the lever'23 is depressed, the feed finger is drawn back along the stay strip and the movable cutter l2-is raised to shear the stay strip. I

When the treadle is releasedv and the arm I 23 is raised by the spring 25, the cutter will lever 23.

be moved. downward out of the path of the stay strip, and the feed finger 26 will be movedforward, feeding a certain length of the stay strip from underneath the shearing blade, so that it may be readily caughtb the feeding mechanism of the machine. stop screw 37 engages the guiding plate 14: and limits the downward movement of the As clearly shown in Fig. 6, the lug 34: is tapered toward its upper end, and forms a cam surface cooperating with a spring 15. When the cutter is in the position shown against the movable cutter 12 is very' slight. As the cutter-is raised, the spring sliding along the cam surface o the pin 34' will increase the pressure, so that a. maximum pressure is obtained during the time of out:

I ting, and the pressure is released at other times, so 'as to relieveexcessive wear on the cutters.

Having thus particularly escribed my in- ,VGIltiOl'l, what I claim as new and,desi-rejtov .secureby LettersPate'nt'isP- g In a stay cutting attach cut, the combination of a movable cutting blade, ashearing blad'e codperating therewith, a spring .in Fig. 6, the pressure of the spring 15 for normally holding said movable blade retracted, a rock lever for operating said movable blade, a feeding finger operated by said rock lever, and an independentspring 7'3. 2. In a stay cutting attachment, the com- 1 for controlling said rock lever.

bination with a stationary shearing .blade underneath which the tape is guided, a movable cutting blade cooperating with said stationary blade, a spring for depressing.

said movable blade, a stop for limiting; the

downward movement of said'blade, a rock lever for raising said blade, a spring for moving said rock lever in a direction to release. the movable blade and a stop for limiting the movement of said rock lever by said spring.

3. In a stayfcutting attachment, the com cutting action, and means for operating said movable cutting blade.

4. In a stay cutting attachment, the combination of a movable cutting blade, a shearing blade coiiperating therewith, a spring for pressing said movable cutting blade against the shearing blade, a tapered v I carried by said movable blade and adapted to beengaged by said spring for increasing the spring pressureof the movable blade against theshearing blade as the movable blade moves, forward for its cutting action, I

and means for ting blade. I

5. In a stay cutting attachment, the com-- operating said movable cuting blade cooperating therewith, a spring for pressing said movable cutting blade against the shearing blade, a tapered pin bination of a movable cutting blade, a shearcarried by the movable blade and adapted to H be engagedzby said spring for increasing the spring pressure of the movable blade against the shearing blade as themovable.

blade moves'forward for its cutting action," .a spring for normally retracting said mov-.

able cutting blade, means cooperating with said tapered pin for limiting the retracted '8 movement of said blade, and means for mov-' ing said blade for it'scutting action.

" 6. In a stay cutting attachment, the combination of a movable cutting blade, in. shearing blade cooperating therewith, a spring for pressing said movable cutting blade against the shearing blade, atapered pin carried by said movable blade and adapted Y to be engaged by said spring for increasing '1. the spring pressure of the "movable blade against the shearing blade as the movable blade moves forward for its cutting action,

means for operating said movable cutting In testimony whereof I afix my signablade, and a feeding finger operating to feed ture in presence of two Witnesses.

the stay between the cutting blades when BENJAMIN V. KERSHNER. the same are separated, said feeding finger Witnesses: 5 being actuated by means for operating said E. H. COWLES,

movable cutting blade. DE FOREST D. HAWLEY. 

